The Globe and Mail reports in its Friday edition that Rio Tinto PLC is poised to become the world's largest miner, and by far the biggest player in Canadian critical minerals, by acquiring rival Glencore PLC in a $70-(U.S.)-billion-plus takeover. A triple-bylined item led by Andrew Willis reports that on Thursday, Glencore and Rio Tinto said in separate statements that the two companies are in "preliminary discussions" on an all-share merger in which Rio Tinto would absorb its Swiss-based rival. London-based Rio Tinto has a $139-billion (U.S.) market capitalization, making it about twice the size of Glencore. The two miners published the statements after the Financial Times reported that they were in merger talks. Major mining companies have been consolidating and committing billions of dollars to develop properties containing copper and other critical minerals. The deal would likely have policy implications in Ottawa, where Prime Minister Mark Carney's government has included critical-minerals mines among the major economic-development projects it is promoting as a counterbalance to the increasingly protectionist trade policy of the U.S. The feds in December approved Anglo American's takeover of Teck Resources.